HIGH

Weather Hazards & Sea Conditions

Navigating bad weather, local wind funnels, and confused seas in Prince William Sound.

Prince William Sound Weather Hazards

Prince William Sound is buffeted by winds sweeping in from the open waters of the Gulf of Alaska and cold air pouring off the massive glaciers of the Chugach Mountains. While summer weather is often pleasant and calm between May and August, conditions can change with extreme speed. Strong winds and steep waves as high as 12 feet can suddenly appear, particularly in exposed bays and channels.

Key Weather Phenomena to Watch

1. High Winds and Local Funnels

High winds and heavy seas are frequently caused by pressure differences between Cook Inlet and Prince William Sound. This pressure gradient generates severe localized winds:

  • Whittier to Shotgun Cove: A notorious wind funnel in Passage Canal where high winds and chop are extremely common. These conditions sometimes (but not always) diminish as you approach Trinity Point and Decision Point.
  • Glacial Fjords: Cold air flowing down glaciers creates strong, cold catabatic winds (gravity-driven downslope winds) that blow straight out of deep bays.

2. “Confused” Seas

A highly hazardous wave phenomenon occurs at the meeting points of several major waterways:

  • South End of Port Wells: Where Blackstone Bay, Cochrane Bay, Passage Canal, and Wells Passage meet. Winds funneling down Port Wells mix with wind and wave patterns originating in the neighboring bays.
  • The Result: The mixing winds create steep, multi-directional chop with no predictable wave pattern, known to mariners as a “confused” sea. Confused seas also occur regularly inside Blackstone Bay and Icy Bay.
  • Long Fetch Waves: Strong easterly winds blowing over a long stretch of open water (known as fetch) can generate large, regular wave trains that create rough, punishing sea conditions in the relatively open Southcentral area of the Sound.

Safety Guidelines for Mariners

  • Expect and Plan for Delays: Never operate under a rigid schedule. Prince William Sound demands patience. If weather conditions worsen, seek the nearest sheltered anchorage or beach immediately. It is always better to be on the beach wishing you were on the water, than to be on the water wishing you were on the beach.
  • Relay Your Status: If you seek refuge, immediately relay your updated position and status to the contact person holding your float plan.
  • Monitor the Weather Continuously: Never rely on a single morning forecast. Constantly watch the skies and monitor marine weather broadcasts.

How to Obtain Marine Weather Forecasts in PWS

Before departing and while underway, always obtain the local forecast for Area 2C (Prince William Sound):

  1. VHF Marine Radio: Tune to WX-2 in the Whittier and Cordova areas, and WX-1 in the Valdez area for continuous NOAA weather broadcasts.
  2. NOAA Marine Weather Online: Visit www.weather.gov/afc and select Prince William Sound, Passage Canal, or Port Valdez.
  3. Alaska Weather Line (Phone): Call 1-800-472-0391 and enter 3144 for Prince William Sound or 3145 for Passage Canal.
  4. Valdez National Weather Service Office: Call 907-835-4505 directly.
  5. Whittier Harbormaster: Call 907-472-2330 or use the push-button weather box at the Whittier triangle kiosk.
  6. Automated AM Radio: Tune your vehicle’s AM radio to 1610 in the Whittier tunnel staging area.
  7. HF-SSB Radio (Large Vessels): Monitor 4125 kHz for regular USCG and NWS scheduled weather broadcasts.